The present patent application claims its date of conception from its Provisional Patent Application filed on Apr. 5, 2008, Entitled “Enlarged Volumetric Exposure for Total in Place Oil & Gas Recovery through Liquid Only Inflow”. With US Postcard PTO number—61123004.
The present invention is an improvement application to a “Continuation in part” (CIP) to U.S. patent application Ser. No. application to. 10/340,818 above filed Apr. 21, 2006, with US CIP filing Ser. No. 11/408,413, now an issued patent with U.S. Pat. No. 7,506,690 entitled “Enhanced Liquid Hydrocarbon Recovery by Miscible Gas Injection Water Drive”. The principal novel improvements it discloses are enlarged wellbores vertical and optionally horizontal and/or deviated for increased volumetric exposure by expandable liners or casing with optional sand screens on the exterior FIG. 4A, and for a larger O.D. downhole liquid displacer (DLD) tool FIGS. 3, 4 & 5, for higher volume and pressure operations and for increased exposure to liquid and gaseous hydrocarbons in their formation FIGS. 6 through 13.
Also a preferred one of the outside centralizer guides shown in FIGS. 14, 15, & 16, or other similar centralizer guides types are added to the outside of the body and screen section on this inventions vertical downhole liquid displacer (DLD) tool to keep this vertical DLD liquid production tool as vertical as possible in the wellbore for its ideal, and best assured operation possible, especially where slightly deviated or crooked wellbores exist above the pay zones.
Concerning the present inventions use of an Expandable liner and sand screen FIG. 4A shows how an expandable liner is installed in the wellbore. Then the vertical DLD tool and production tubing string are installed in the vertical wellbore.
To reduce the loss of diameter each time a new casing string or liner is set Expandables are applied in wellbores in order to reduce the loss of diameter each time a new casing or liner is set, a cold working process has been developed whereby said casing or liner can be expanded by up to 20% in diameter after being run down-hole. For this purpose, an expansion tool that exceeds the inner diameter of the tube by the required amount of expansion is forced through the pipe. This is done either hydraulically, by applying mud pressure, or mechanically, by pulling a cone shaped\tapered expansion tool. The expansion needs to be reliable, when expanding several below the surface. This can be from 30 ft-6,000 ft in length.
Applications can be groups in two main categories; 1) Cased hole and 2) Open hole. Cased hole work is mainly down during the work over or completion phase of a well. The open hole products are used during the drilling period of a well. The products developed and made available now in cased hole that work, are the expandable liner hanger and the cased hole clad. The expandable liner hanger is a product with better thru bore and envisaged higher reliability. The Case hole clad provide a casing patch across a damaged section of casing, or to close off previously perforated casing. This product has two main advantages—minimal through bore loss [basically two times the wall thickness of tubular being expanded] and high pressure integrity performance.
For open hole applications where expandable technology brings real advantages as described in this disclosure these products are available; 1) “open hole liner” and 2) “open hole clads.”
Applications of expandable technology exist, for example water shut off, and casing repairs in old wells, but absolutely none of the oil or gas industries prior art that make use of this technology show this inventions downhole liquid displacer tool applications or employ any pressure displacement drive of liquids only inflow from wellbore bottom up to surface, while retaining gas in the formation or producing it separate.
The present invention discloses larger wellbores though expandable liners with optional sand screens on the exterior in liquid or gaseous hydrocarbon reservoirs, for employing its systems and methods for effectively retaining solution gas in place during production of original solution gas saturated oil, and/or for returning indispensable solution gas saturation to in place crude oil depleted of solution gas saturation, by miscible gas injection to pre-planned optimal solution gas saturation, then efficiently recovering that original or returned solution gas saturated crude oil out of it's formation above its critical bubble point pressure for total in place oil recovery. While benefiting the World's environment by eliminating the burning of natural gas to produce oil, which will significantly help eliminate global heating and oil well blowouts through eliminating the flaring of natural gas to the atmosphere. Also both onshore and offshore oil well blowouts will be considerably reduced by not flowing or producing gas with crude oil.
When the present invention is applied in natural gas reservoirs gas production is flowed undisturbed by liquids separately though the wells (tubing to casing) wellbore annulus to surface, while incoming liquids are removed separately downhole though its improved large liquid displacer tool into the production tubing and when needed artificially lifted onto the surface for total in place gaseous and liquid hydrocarbon recovery. Thus both separate oil and/or gas recovery systems substantially benefit from now enlarged Volumetric exposure for both vertical and horizontal boreholes screened from formation sand, to now attain close to total in place crude oil and/or natural gas recovery.
The present invention is also disclosing added outside centralizing guides with expandable ribs, or extended medal ridge, or clip on or push on synthetic material guides (along with all other industry used types) see FIGS. 14, 15, and 16, specially adapted for or special made for this present invention's Downhole Liquid Displacer Tool's outside body, as well as for its outside upper sand screen section (see FIGS. 3 & 5), to guide the tool downhole through the oil or gas wells wellbore, and protect its compressible fragile screen section, and particularly to better hold the tool in efficient vertical place by the pay zone. These important guides are shown in FIGS. 14 through 16, but not on FIGS. 3 though 13 schematic drawings, however are to be considered present. The DLD label on all drawings from FIG. 3 though FIG. 13 is hereafter called the DLD as the tool now has included improved outside centralizer guides The inventions DLD includes an approximant 24 ft. size or longer vertical float and a valve arrangement, and once installed on the production tubing string in the oil or gas well's wellbore bottom remains immersed in the well's downhole surrounding formation liquids. So when the DLD's top open float becomes full of liquid, an open conduit is provided direct from the hydrocarbon reservoir to the producing tubular string. At that time when automatically the liquid is displaced by gas pressure out of the DLD's interior float, the float rises due to its increased buoyancy and its valve closes to prevent the entry of any and all formation and wellbore gas into the producing tubing string.
The inventions DLD thus includes its vertical float cylinder (closed at the bottom and open at the top) activated double valve system (see FIG. 3), which opens when the DLD full of liquid and submerges and becomes buoyant rises and closes when that liquid is displaced by differential gas pressure through its opened double valve into the tubing string. Importantly this flotation system within this DLD is configured to operate in an n vertical or substantially vertical orientation. If the wellbore is deviated up hole above the open hydrocarbon production formation, and thus the bottom operating DLD it may possibly affect it's float and valves successful operation. Thus the novel addition of vertical wellbore adjusting guides on the outside of the DLD tool's body and equally essential on its sand screen's connecting steel collars sections where formation liquids enter the DLD tool's screen (see FIGS. 3, 4, and 5). Thus when the DLD's vertically held float is open, the open float allows liquid to be transmitted by gas pressure within the wellbore from the producing formation upward through the production tubing string which is positioned above the DLD's head and then to be lifted to the surface by pressure differential alone or with most types artificial lift, (preferably fluid operated gas lift valves). Although drawings don't show the centralizer guides, it is now established that one type of another of centralizer guides will be used as required in that type of wellbore. Although the present inventions DLD may be also used without these guides as the wellbore permits, and or it's preferred. Also the DLD's sand screen may be omitted in non-sandy wells where open perforations can be used alternatively. Also its double valve may be omitted for a single valve when feasible. Also its fabrication materials and as its OD size and length may substantially vary according to need. It is usably run with a bull plug on its bottom, but may be run without one as most feasible, for sand settlement etc. In other words the present inventions DLD basic designs may vary according to its required workable function.
Prior to which this invention is an improvement for, the world oil industry at the present recovers crude oil reserves through industry procedures that allow reservoir gas within the formation to flow into the wellbore and to the surface with the oil. This worldwide oil production method loses the majority of what is originally recoverable crude oil as it becomes unrecoverable and devoid of its solution gas which maintains the oil fluid, highly mobile and thus recoverable. As a result due to the crude oil losing its solution gas saturation, that oil becomes viscous and unrecoverable. The present invention discloses and teaches how to permanently transform this industry practice through recovering in place oil for its reservoir into it disclosed enlarged wellbores without loosening its solution gas saturation, being optionally benefited by a surface injected down structure water drive pressure.
The present inventions increased hydrocarbon recovery methods function through its further disclosed methods of increasing borehole sizes though expandable liners and sand screens being permanently set into the highest maximum O.D, size boreholes possible both vertical and horizontal. This is done by “under-reaming” the open hole using an expandable bit which can be “bi-center” or “tri-center”.
The expandable casing or liner string which is being run through, hung into and expanded below large sizes of casing from 9⅞ to 11¾ to 13⅜, up to 16-in. then run into the open hole, cemented therein, and expanded by a hydraulic driven solid cone which also expands and permanently seals the expandable hanger into the upper casing string. I.e. the present inventions expandable liners are run through the first string, hung therein, and expanded to an ID close to or the same as the first upper casing string. This process creates what are called “mono-bores” which maintain the same ID to the bottom of the hole.
In vertical maximum O.D. size by the downhole liquid hydrocarbon formation and in horizontal for maximum size O.D. back into the same liquid hydrocarbon formation, which is also drilled to maximum length for recovering solution gas saturated oil above its bubble point pressure, And also for providing a larger volumetric O.D. vertical and horizontal area with an greatly extended horizontal length area for miscible gas injection to return solution gas saturation to in place oil in oil reservoirs.
This same process is applied in natural gas formations for maximum gas recovery, however optionally miscible gas can be injected into problem condensate blocked areas of the producing gas formation. While liquid burdened natural gas formations are immediately liberated from all incoming liquid burdens by the present inventions recovering natural gas though it's wellbore conduit and formation liquids through the present invention's liquid displacer tool though the production tubing string conduit, for total in place recovery of now liquid free natural gas and liquid hydrocarbons respectively. While water is removed and disposed of at the surface.
The prior art sited and present industry practices do not practice nor benefit from the present inventions centralizer guides on the downhole liquid displacer tool and its sand screen section, helping maintain that tool vertical in the lower wellbore by the open hydrocarbon formation for better assured vertical operation.
Or by the present inventions beneficial addition of enlarged volumetrically exposure to hydrocarbons through its enlarged vertical and horizontal boreholes into that hydrocarbon reservoir. Such increased volumetric exposure consisting of increased maximum O.D size boreholes by the formation vertical pay zone, and increased horizontally length and O.D. size boreholes into that same pay zone which are beneficially obtained with expandable liners and screens set along their specially enlarged O.D. borehole walls, as the invention's downhole liquid displacer tool produces and recovers by wellbore to production tubing pressure differential the total in place solution gas saturated oil incoming production above its bubble point pressure, with applied wellbore wellhead to formation gas pressure control methods from that formation for total in place oil gas recovery. Importantly the large O.D. wellbore allow for larger O.D. downhole liquid displacer tools which give that tool a larger O.D. float to now open the float double valves 3/16″ pilot valve with a greater downward weight pull, thus opening at higher wellbore pressures,
Plus a larger O.D. DLD has a larger O.D. discharge to be above the it opening valve, for better liquid flow upward, thus alimenting the tight friction back drag to liquid flow of the smaller tools small discharge tube, which held back it daily liquid flow production. The larger 6″ O.D.DLD is calculated to now handle up to 15,000 bbl a day of oil flow as found in offshore Cantarell Complex of Mexico.
Nor do today's gas production Industry practices nor any prior art benefit from the present invention's producing natural gas flow from maximum O.D. size boreholes and increased horizontally length and O.D. size boreholes for maximum volumetric exposure to in place natural gas, flowing this gas to surface completely free of any liquid burdens in the wellbore by removing all incoming liquid separately though the present inventions liquid displacer tool into the production tubing, where these liquids are plunger lifted by tubing pressure operated gas lift valve injected gas to surface, while optionally miscible gas can be injected into condensate blocked areas of the gas formation to enhance flow of blocked areas for total in place gas recovery.
While absolutely none of the industry prior art using expandable technology, show a downhole liquid displacer use, or any pressure displacement drive of liquid only inflow from wellbore bottom up to surface in crude oil or natural gas wells, while conserving natural or injected gas in the formation for gas drive in oil wells or producing it open flow separate to surface.
The present invention's systems and methods will recover a high percentage of the total in place crude oil in most recovery stage crude oil reservoirs, and almost all total in place gas from natural gas reservoirs. The vital and major improvements of the present invention are hereafter disclosed are urgently needed by the world oil industry that presently recovers only 10-30% of the total in place crude oil, and rarely reaches 40% oil recovery. While natural gas recovery is lower than 60% recovery in very little too average liquid burdened natural gas reservoirs and a considerable amount less recovery in seriously liquid burdened gas reservoirs. The systems, methods, improvements and advantages of the present invention disclosed are very much novel to the industry and are clearly not disclosed in the prior art, and are hereafter disclosed.